Gestational hypertension and pre-eclampsia and risk of spontaneous premature rupture of membranes: A population-based cohort study

Objective: To examine whether gestational hypertension and pre-eclampsia are associated with spontaneous premature rupture of membranes (PROM).

Methods: A retrospective, population-based cohort study was conducted in Hebei, Zhejiang, and Jiangsu provinces in China from 1993 to 1995. After excluding women with missing data of exposure and outcome, history of chronic hypertension, multiple births, and babies with major birth defects and ambiguous sex, this study comprised 199 231 singleton live births. Logistic regression was used to evaluate the association, adjusting for potential confounders.

Results: The incidence of PROM was 17.7% and 8.9% in women with gestational hypertension and pre-eclampsia, respectively, and 5.9% for the normotensive group. Compared with normotension, gestational hypertension was associated with an increase in the odds of PROM of 4.21 times (95% confidence interval [CI] 3.77-4.70), while pre-eclampsia had an increase of 2.27 times (95% CI 1.78-2.88). Additionally, women with hypertensive disorders of pregnancy had higher risks for term PROM (adjusted risk ratio [RR] 3.83, 95% CI 3.43-4.27) than preterm PROM (adjusted RR 3.10, 95% CI 2.18-4.41). Consistent results of the association were also observed in the sensitivity analyses.

Conclusion: Gestational hypertension and pre-eclampsia were associated with an increased risk for PROM. Increased odds were observed for term PROM compared with preterm PROM.